The symptoms & features of Kleefstra Syndrome may include:

Physical Features

  • ‚ÄčHypotonia (Low muscle tone)
  • Unusually small head (microcephaly)
  • A wide, short skull (brachycephaly)
  • Distinctive facial features which could include eyebrows that grow together in the middle, sunken appearance in the middle of the face, widely spaced eyes, nostrils that open to the front rather than downward, a protruding jaw, rolled out lips, and a large tongue
  • High birth weight and weight control issues as children/adult
  • Unusual hands/feet (position, shape, or size)
  • Dental abnormalities
  • Skin that may be discolored or lighter in areas
  • Anal atresia

Neurological Features

  • Intellectual disabilities
  • Limited or absent speech capabilities
  • Various global developmental delays
  • Autistic-like features and characteristics
  • Seizures
  • Sleep disorders
  • Behavioral difficulties
  • Visual impairments
  • Difficulty swallowing
  • Impairments in hearing (may have several inconclusive hearing test results)
  • General loss of interest and enthusiasm as they get older
  • Regressive behavior as they get older

Clinical Features

  • Structural brain abnormalities
  • Congenital heart defects
  • Abnormalities of the genitalia
  • Tendency to develop severe respiratory infections
  • Kidney abnormalities